Effects of Key Travel Distances on Biomechanical Exposures and Typing Performance During UltraLow Key Travel Keyboards

2017 ◽  
Vol 61 (1) ◽  
pp. 981-985 ◽  
Author(s):  
Jonathan Sisley ◽  
Kiana Kia ◽  
Peter W Johnson ◽  
Jeong Ho Kim
Keyword(s):  
Risk Factors ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Flexor Digitorum Superficialis ◽  
Extensor Digitorum Communis ◽  
Physical Risk ◽  
Physical Risk Factors ◽  
Small Muscle ◽  
Flexor Digitorum ◽  
Travel Distances

This study investigated how differently ultra-low key travel (< 2.0 mm) keyboards affect typing force, muscle activity, and typing productivity as compared to a conventional keyboard. In a repeated-measures laboratory-based study with 20 subjects, we collected and compared typing forces, muscle activity in extrinsic finger muscles (flexor digitorum superficialis (FDS) and extensor digitorum communis(EDC)), and typing performance among five keyboards with different key travel distances (0.5, 0.7, 1.2, 1.6, and 2.0 mm). The results showed that there were differences between ultra-low key travel keyboards (0.5, 0.7, 1.2 and 1.6 mm) and a conventional keyboard (2.0 mm) in typing force (p < 0.001), muscle activity (p > 0.07) expect for FDS (p < 0.01), and typing speed (p < 0.001). However, in general, the differences appears to be practically small: muscle activity (less than 1.3%) and typing force (less than 0.5 newton). The study findings indicates that the ultra-low key travel keyboards may not increase or decrease physical risk factors and typing performances as compared to conventional keyboards.

Characterizing exposure to physical risk factors among reforestation hand planters in the Southeastern United States

2018 ◽  
Vol 66 ◽  
pp. 1-8 ◽  
Author(s):  
Robert F. Granzow ◽  
Mark C. Schall ◽  
Mathew F. Smidt ◽  
Howard Chen ◽  
Nathan B. Fethke ◽  
...  
Keyword(s):  
United States ◽  
Risk Factors ◽  
Southeastern United States ◽  
Physical Risk ◽  
Physical Risk Factors

scholarly journals Quantitative Measures of Physical Risk Factors Associated with Work-Related Musculoskeletal Disorders of the Elbow: A Systematic Review

2019 ◽  
Vol 16 (1) ◽  
pp. 130 ◽  
Author(s):  
David H. Seidel ◽  
Dirk M. Ditchen ◽  
Ulrike M. Hoehne-Hückstädt ◽  
Monika A. Rieger ◽  
Benjamin Steinhilber
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Musculoskeletal Disorders ◽  
Well Being ◽  
Special Focus ◽  
Factors Associated ◽  
Work Related ◽  
Work Related Musculoskeletal Disorders ◽  
Physical Risk ◽  
Physical Risk Factors

Background: Work-related musculoskeletal disorders at the elbow are a common health problem, which highly impacts workers’ well-being and performance. Besides existing qualitative information, there is a clear lack of quantitative information of physical risk factors associated with specific disorders at the elbow (SDEs). Objective: To provide evidence-based quantitative measures of physical risk factors associated with SDEs. Methods: Studies were searched from 2007 to 2017 in Medline, EMBASE, and Cochrane Work. The identified risk factors were grouped in main- and sub-categories of exposure using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework for rating evidence. Results: 133 different risk-factor specifications were identified in 10/524 articles and were grouped into 5 main- and 16 sub-categories of exposure. The risk factors were significantly associated with lateral epicondylitis, medial epicondylitis, or ulnar neuropathy. Significant risk factors such as wrist angular velocity (5°/s, with increasing prevalence ratio of 0.10%/(°/s), or forearm supination (≥45° and ≥5% of time combined with forceful lifting) were found. Conclusions: This review delivers a categorization of work-related physical risk-factor specifications for SDEs with a special focus on quantitative measures, ranked for evidence. These results may build the base for developing risk assessment methods and prospective preventive measures.

Comparison of Muscle Activity during Use of Computer Pointing Devices in Cad Operators

2000 ◽  
Vol 44 (37) ◽  
pp. 633-636 ◽  
Author(s):  
Pat Tittiranonda ◽  
Bernard Martin ◽  
Stephen Burastero
Keyword(s):  
Muscle Activity ◽  
Index Finger ◽  
Neck Muscles ◽  
Electromyographic Activity ◽  
Flexor Digitorum Superficialis ◽  
Upper Trapezius ◽  
Extensor Indicis Proprius ◽  
Significant Difference ◽  
Experimental Mouse ◽  
Flexor Digitorum

This study examined the use of four different computer pointing devices on surface electromyographic activity of the index finger, forearm and shoulder/neck muscles among CAD operators in the workplace. Subjects were randomly assigned to use their own mouse, a trackball, a joystick mouse or an experimental mouse. Results showed that there was a statistically significant difference in muscle load for the upper trapezius, extensor indicis proprius, and extensor carpi ulnaris across pointing devices for CAD operations. The flexor digitorum superficialis muscle load remained relatively constant when all pointing devices were compared.

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